High tension circuit interrupter



May 24, 1932.

D. C. PRINCE ET AL HIGH TENSION CIRCUIT INTERRUPTER Filed May 19, 1951Inventors David C. Prince, William Tur'nloerwrwg, bg f/@M7 MM Their-Attor-rwelsj.

`Patented I May 24, `1932 Latent UNITED STATES lParleur OFFICE DAVID C.PRINCE, 0F SCHENECTADY, AND WILLIAM'T'UBNPENY, OF ALBANY, N'Iltil"-YORK, ASSIGNORS T0 GENERAL ELECTRIC 'COMPANY, A CORPORATION OF NEW YORKI Application led lay 19,

Our invention relates to high tension circuit interrupters, lnoreparticularly to mult1- ple break interrupters of the oil blast typewherein pressure generating arcs are formed 5 to cause i'low ofextinguishing liquid at high velocity through and across arcs in seriesin v'the circuit to be interrupted.

As is well known, the oil circuit breakers used in modern high tensionpower transmission systems, as for instance of 220 kilovolts, aremassive, expensive, and require a large amount of space. The. hugecircuit breaker tanks`on which the heavy lead-in insulating bushings-aresupported contain in most instances several thousand gallons of highgrade insulating oil which is inflammable and a potential fire hazard sothat a large factor of safety in the breaker design ishecessary.Likewise powerful andexpensive operating mechanisms are required toeffect operation ofthe circuit breakers at the required speed. In brief,high `tension, oil circuit breakers in present use involve high initial,installation and maintenance costs and likewise involve the disadvantageof requiring a large amount of space and overhead clearance. 1 l

A principal object of our invention is the pr0vision`of an improved hightension circuit interrupter employing an arc extinguishing l liquid, asoil', which shall be compact and of small mass, lrugged and simple inconstruction, and positive and reliable in operation.

Our invention will be more fully set forth in the followingdescriptionreferring to the accompanying drawings, and the features ofnovelty which characterize our inventionv will be pointed out withparticularity in the claims annexed to and forming a part of this Lspecification. A

Referring to the drawings, Fig.- 1 is a partial cross-sectional,elevational view of a high tension circuit interrupter embodying ourinvention, Fig. 2 is a partial` sectional plan view as viewed frombeneath, and Fig. 3 is a cross sectional view taken along the line 3-3of Fig. 1. i

Referring to Fig. 1 of the drawings the 5 high tension circuitinterrupter comprises a generally tubular housing, horizontally ar- Aallconnected in series and immersed in an insulating and arc Iextinguishingliquid, 21,

t the insu atin HIGH TENSION CIRCUIT INTERRUPTEB 1931., Serial No'.538,580.

ranged, formed bv a pair of strong insulating l tubes 1 and 2 joined bya flanged coupling member 3 which is in turn supported b the insulatingshell 4. The insulating tu es 1 and 2 are preferably of laminatedinsulating material impregnated with a suitable resinl ous productforming a mechanically strong structure. For the purpose of convenience.in illustration the part of the housing formed by the insulating tube 2is but partially shown, it being understood that the insulating tube 2and the structure associated therewith are similar to and substantiallyduplicate of that shown in connection with the insulating tube 1.

The terminals of the circuit interrupter comprise connecting means asthe binding posts 5 and 6 extending through the end caps 7 and 8suitably secured, as by screw-thread ed engagement, to the opposite endsof the 'm housing respectively. The circuit interconplurality of pairs`of contacts connected inf series by flexible conductors, certain pairsof contacts as 9-10 serving as pressure generating contacts and othercontacts'as 13-14 and 15-16 related thereto. functioning to interruptthe circuit in a manner hereinafter described. In the present instanceeachhalf of the circuit breaker housing contains two pressure generatingbreaks, as 9-10 and 11- 12, and four main current interrupting breaks,as 13a-14, `15--16, 17-18 and 19`20 as. oil, conta-ined in the housing,it of course being understood that the number and arrangement of breaksin series may be varied in accordance with the particular operatingvoltage and other considerations.

The contact operating mechanism com= prises an operating rod 22 ofstrong insulate ing material, as wood, vertically movable within atubular metallic guide 23 extending through and secured as by welding toa clampln plate 23' closin the upper end of shell 4. uitable actuatinmeans (not s own) disposed at the base o the insulating shell may beoperatively con= i nected to the rod 22 for imparting movement thereto.For the purpose of opeiiingthe circuit interrupter at high speedindependently of the actuating. means, the rod 22 is Y connected througha link 24 to a rod 25 excompression spring 29 serving as an energy.

storing devi/ce for causing circuit opening movement. Motion istransmitted from the operating .rod 22 to the switch cont-acts through acrank 30 pivoted to the coupling 3 as at 31. An arm 32 of the crankextends through a slot 22 in the guide tube 23 and is pivotallyconnected to the rod 22. Another forked arm 33 of the crank engages across pin 34 interconnecting a pair of parallel contact operating rods35 and 36 of strong insulating material, as maple, extendinghorizontally within the breaker housing so as to cause reciprocatorymovement of said rods in response to rotation of the crank.

Referring more particularly to Fig. 2, the parallel rods 35 and 36 serveto guide and actuate the movable contacts 10 and 12 of the pressuregenerating contacts, and 14, 16, 18 and 20 of the main currentinterrupting contacts, and likewise the corresponding movable contactsdisposed within the insulating tube 2. Each movable contact is connectedto a crossbar 37 mounted for sliding movement on the rods 35 and 36, thecrossbar and likewisethe movable contact being normall biased towardsclosed circuit position by tlie coilsprings 38 disposed between thecrossbar 37 and the insulating sleeves 39 which are pinned or otherwisesecured to the rods 35 and 36. For the purpose of moving the crossbarsin the opposite direction the insulating sleeves are of suitable lengthto engage and move the crossbar of the adjacent contacts. f 7

The main mounting and supporting structure for the contacts and for therods 35 and 36 comprises a strong insulating partition 40 of laminatedwood or the like disposed within the housing as best illustrated in Fig.3,

formin a lower pressure generating chamber an an upper relief chamber,the partition 40 being suitably positioned and braced by the bolts 41and insulating spacing blocks 42 disposed at opposite ends of thehousing. The mid-portion of the partition 40 is likewise supported andbraced by a plate 40 which is secured as by Welding'to the couplin 3,the guide tube 23 extending freely throug the partition 40 and plate 40.The crank 30 ts snugly within a slot 30. formed in the partition 40 sothahcom'munication between the upper and lower chambers is restrictedexcept as hereinafter described.

Opposite the main current interrupting contacts in the partition 40 arepressure relief openings 43, 44, 45 and 46, each pair of contacts beingpositioned within an insulat ing tube or thimble 47, open at bot-h ends,secured in any suitable manner within the corresponding relief openingto the partition 40 as by threaded engagement with a retaininginsulating Awasher 48. As clearly illustrate in Fig. 1 the oil level isbut a-short distance above the partition 40 and the relief openings,thereby maintaining a low pressure head at those points.

Each pair of the main current interrupting contacts is similarinarrangement, the stationary contact 13 ofthe break1314 for exampleextending through and clamped to the wall of the corresponding thimble47 by suitable means 49 servin likewise to connect one end of a flexiblebralded conductor 50 to the stationary contact. The coacting movablecontact 14 which is carried by a crossbar 37 extendsthrough andisslidably mounted'and supported within the o posite wall of the thimbleso as to make an break contact with in the thimble Aand adjacent therelief openring 43. The remaining main current interrupting contacts aresimilarly mounted within thimbles 47 so that further description thereofis unnecessary. v

The pressure generating contacts' on the other hand are remotelypositioned from the relief openings in the partition 40 and arepreferably placed intermediate a pair of main interrupting contacts.Referring by way of example lto the pressure generating contacts 9 and10, the stationary contact 9 is suitably secured to one arm of-aU-shaped member 51 clamped to the lower side of the partition 4() by abolt 41, the U-shaped member likewise supporting and guiding the movablecontact 16 of the adjacent pair of main contacts. The movable contact,10

-is carried by -crossbar 37 in a manner above described and iscontrolled by movement of the rods 35 and 36. The pressure generat- -ingcontacts 11 Aand 12 are similarly ar-Alf ranged and constructed.

all connected in series by the flexible braided' conductors 50connecting a movable contact of one pair with the stationary contact ofthe next pair in series therewith. AV braided e conductor 52 likewiseconnects the sets of contacts on opposite sides of the housing in seriesthrough the coupling 3, the contacts being connected to theterminals 5and 6 by the conductors 53 and 54 respectively. t

For the purpose of venting gas from the upper relief chamber and forpreventing expulsion of oil therefrom, the housing 26 forms a separatingchamber of Athe Well known pebble type, the chamber having a lowerperforated wall 55 supporting a body of pebbles, 56. The c ap 28 islikewise perforated as at'57 so that gas may be freelyvvented throughthe separating chamber While preventing expulsion of oil therefrom.

In actual practice a grading reslstance (not shown) may be connected inparallel across the terminals, taps from vthe resistance being suitablyconnected across theindividual pairs of main current interruptingcontacts for the purpose of equalizing the voltage at eachv pair ofcont-acts. This arrangement, however, forms no part of our presentinvention and has been omitted for the purpose of clarity sinceillustration Athereo is not necessary for complete understandingof ourinvention.

The operation of the circuit interrupter is as follows: When the circuitinterrupter is in the closed circuit position illustrated in F ig. 1wherein each pair of contacts is in engagement, the spring 29 is undercompression tending to rotate the crank 30 in a counter-clockwisedirection to cause opening movement of the parallel rods 35 and 36.lWhe-n the operating rod 23 is released by tripping mechanism of anysuitable type either at the option of the operator or in by thesecontacts generate, as is wellknown,

high pressure in that regibn. The main current interrupting contactshowever are so arranged with respect to the respective relief openingsthat the arcs drawn between the same are directly in the path of flow ofoil` exhausting int-o the upper relief chamber. By positioning a pair ofpressure generating contacts between a pair of main current interruptingcontacts, sufficient pressure is generated within the lower pressurechamber to cause a blast of oil at high velocity upwardly through eachof the thimbles and associated `the thimble by the-corresponding maincontacts is traversed and effectively extinguished by the oil blast inexhausting into the upper relief chamber which maybe at atmosphericpressure. .-In view of the fact that all main current interruptingcontacts are in series and are opened .practically simultaneously, thearc at each pair of main contacts is traversed simultaneously by an oilblast so that in` terruption of the circuit is positive and effective.Furthermore, the arcs formed Within the thimbles47 have no chance toshift from or dodge the oil blast since the entire arc space issubjected to the blast of oil.

The switch .closing operation is edected simply by downward' movement ofthe ing rod 22 by the actuating means, causing clockwise movement of thecrank 30 to shift the parallel rods 35 and 36 to the circuit clos-` ingposition, meanwhile compressing the spring 29 for a subsequent circuitopening operation. The springs 38 which normally.

bias the crossbars 37 and the movable contactstowards closed circuitposition serve to resiliently bias the contacts into engagement as wellas provide for overtravel of the opy eratin'g mechanism during theclosing operaoperatu p tion, the insulating sleeves 39 engaging the bars37 in the circuit opening operation.

The operation of a high tension circuit interrupter embodying ourinvention is without appreciable noise and is accompanied by low` gaspressure and very little, if any, oil throw, thereby reducing to anappreciable extent fire hazard. The circuit interrupter moreover for agiven interrupting rating is small and occupies little space andrequires but a few gallons of ,oil as compared with the huge amountrequired by oil circuit breakers now in use. Furthermore, the operatingmechanism may be simple'and have a comparatively low power rating.

Although oil is specifically referred to as the insulating andareextinguishing liquid, it should be understood that other insulating andextinguishing liquids having suitable characteristics may be used. Oil,however,

has the advantage ofbeing a lubricant` as' well so that all moving partsare sufficiently lubricated at all times.

Under certain conditions, as in outdoor operation, an outer insulatingshell of porcelain or the like may be used to substantially enclose theelongated tubular housing, thereby minimizing the cha-nce of lashoverbetween l1ve parts of the breaker.

uff.-

lle() It should be understood that our invention is not limited tospecific details of construction and arrangement thereof hereinillustrated, and that` changes and modifications may occur to oneskilled in the art without departing from the spirit of our invention.

What We claim as new and desire to secure vb L tt f t relief openmg sothat-the are drawn withm y e ers Patent o he Umted States 1S 1. A hightension circuit interrupter comprising a housing having a pressurechamber and a relief chamber communicating therewith through a4plurality of relief openings,

an arc-extinguishing liquid filling said lpressure chamber, and aplurality of pairs of contacts connected in series in said pressure'chamber, certain pairs of said contacts being ings and `across the arcsdrawn between the corresponding adjacent pair of contacts.

2. A. high tension circuit interrupter comprising a housing having alower pressure chamber and an upper relief chamber connecting through aplurality of relief openings, an insulating and arc-extinguishing liquidfilling said lower chamber, a plurality of pairs of contacts connectedin series immersed in said liquid, certain of said pairs of contactspositioned adjacent and opposite said relief openings and other of saidpairs of contacts being remotely positioned with respect to saidopenings, and means operatively connected to said pairs of contactscausing simultaneous'separation thereof so that the arcs drawn betweensaid remotely positioned contacts generate pressure within the pressurechamber to blast extinguishing liquid through said relief openings andacross the arcs formed between the corresponding adjacent pair ofcontacts. l,

3. A high tension circuit interrupter comprising anlelongated-tubularhousing horizontally arranged, a partition in said housc ing forming alower pressure chamber and an upper relief chamber, sald chamberscommunicating through relief openings in said l uid from said pressurechamber throng l each relief opening so that the corresponding pair ofadjacent-contacts is directly in the path ofsaid liquid, and meansoperatively connected to each pair of contacts causing simultaneousseparation thereof so that the remotely positioned contacts formpressure generating breaks for forcing extinguishing liquid at highvelocity through saidrelief openings and across the arcs formed betweenthe corresponding adjacent contacts.

4. A high tension circuit interrupter comprising an elongated insulatinghousing horzontally arranged, an insulating partition dividing saidhousing into a lower pressure chamber and an .upper relief chamber, saidchambers communicating through relief openings in said partition, aninsulating and arc-extinguishin liquid filling said pressure chamber, aplura 'ty of pairs of contacts connected in series lmmersed in saidliquid within the pressure chamber, insulating thimbles mounted in saidrelief .openings and extending into said pressure chamber, certain ofsaid pairs of contacts each arranged to make and breallr contact withina corresponding thimble4 and adjacent its reliefl opening, ot erpairsjof said contacts being remotely positioned with respect to saidrelief openings, and contact operating means causing substantiallysimultaneous separation of each pair of contacts so that the pressuregenerated by arcing between the remotely positioned contacts serves toforce extinguishing liquid at high velocity from said pressure chamberthrough said insulating thimbles to extinguish the arcs formed therein.

l5. A high tension circuit interrupter comprising a housing having apartition dividing the same into a lower pressure chamber and an upperrelief chamber, said chambers communicating. through relief openings insaid partition, a plurality of pairs of contacts connected in seriesWithin said pressure chamber, an insulating liquid in said chamber inwhich said contacts are immersed, certain of said pairs-of contactsserving as main current interrupting contacts positioned adjacent andopposite said relief openings, another pair of said contacts serving aspressure generating contacts positioned intermediatetwo pairs of maincurrent interrupting contacts, and contact operating means effectingseparation of each pair of contacts Aso that arcing at the pressuregenerating contacts forces insulating liquid at high velocity betweensaid main current interrupting contacts to exhaust into. said reliefchamber.

6. A high tension circuit interrupter comprising an insulating tubularhousing horizontally arranged, an insulating partition dividing saidhousing into a lower pressure chamber and an upper relief chamber, saidchambers communicating through relief openings in said partition, aninsulating oil within said pressure chamber, a plurality of pairs ofcontacts connected in seriesl within said pressure chamber, saidcontacts mounted on and supported by said partition, certain pairs ofsaid contacts positioned adjacent and opposite said relief openings, andoperating means causing substantially simultaneous separation of eachpair of contacts so that the arcing pressure generated by the contactsremotely positioned with respectr-to said relief openings forcesindivid- H5 ualblastsof oil through the relief openings and across thearcs formed thereat.

In witness whereofjve have hereunto set

